The view from the top of O’Hare Airport’s newest control tower is breathtaking, offering a 360-degree panorama of the airport and its operations. But the city of Chicago also wants to show off the first floor, where a geo-thermal plant optimizes the tower’s heating and cooling systems, helping to save an estimated $20,000 a year in utilities.

On Earth Day, the South Air Traffic Control tower (SATCT) was awarded the coveted LEED Gold certification, one of the first control towers ever to receive the acknowledgement. It also was one of six O’Hare buildings to be recognized.